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目的通过设置日常接触(0.2μg/kg·bw)和子代最高非致畸(0.8μg/kg·bw)这两个极限剂量,探讨胚胎性腺性别决定期宫内2,3,7,8-四氯二苯并二噁英(TCDD)暴露对子代成年雄性大鼠睾丸形态、精子发生及血清睾酮、雌二醇水平的不同影响。方法孕SD大鼠随机分为TCDD染毒组(0.2和0.8μg/kg·bw)和对照组(玉米油+二甲基亚砜),于GD 8~14天每日定时灌胃染毒。测定90日龄成年雄性子代的体重增重、睾丸总重;睾丸组织切片苏木素-伊红(HE)染色后测量睾丸生精细胞层厚度,计算睾丸间质细胞密度,并使用Johnsen’s Score对睾丸的精子发生进行评价;化学发光法测定血清中睾酮及雌二醇的水平。结果 (1)0.8μg/kg·bw组成年雄鼠睾丸总重明显低于对照组(P<0.05),0.2μg/kg·bw剂量组睾丸总重和体重增加量与对照组相比,差异无统计学意义(P>0.05);(2)两个TCDD组睾丸Johnsen’s Score得分均低于对照组(P<0.05),0.8μg/kg·bw组生精细胞层厚度明显低于对照组(P<0.05),睾丸间质细胞密度组间差异无统计学意义;(3)两个TCDD组成年雄鼠血清雌二醇水平明显下降(P<0.05),睾酮水平组间差别无统计学意义。结论胚胎性腺性别决定期内,孕鼠日常接触剂量和高剂量TCDD暴露均可造成成年雄鼠睾丸组织病理学形态的改变,睾丸生精细胞层厚度变薄,精子发生受损,可能影响睾丸精子生成,造成雄性子代生殖能力降低。
Objective To investigate the effect of intrauterine 2,3,7,8-tetrazine in embryonic gonadal sex by setting daily exposure (0.2μg / kg · bw) and maximum non-teratogenic (0.8μg / kg · bw) Different effects of chlorodibenzodioxin (TCDD) exposure on testicular morphology, spermatogenesis, serum testosterone and estradiol levels in offspring of adult male rats. Methods Pregnant SD rats were randomly divided into two groups: TCDD (0.2 and 0.8 μg / kg · bw) and control group (corn oil + dimethyl sulfoxide). The weight gain and testicular weight of 90-day-old male offsprings were measured. The testicular germ cell layer thickness was measured after hematoxylin-eosin (HE) staining and the testicular interstitial cell density was calculated. The testis Of the spermatogenesis were evaluated; chemiluminescence method for the determination of serum testosterone and estradiol levels. Results (1) Compared with control group, the total testis weight of male rats at 0.8μg / kg · bw was significantly lower than that of the control group (P <0.05). Compared with the control group, the testicular weight and weight gain at 0.2μg / kg · bw (2) Johnsen’s Score of testes in two TCDD groups was lower than that in control group (P <0.05), and sperm layer thickness in 0.8μg / kg · bw group was significantly lower than that of control group P <0.05). There was no significant difference between the testicular stromal cell density groups. (3) Serum estradiol levels were significantly decreased in both male and female TCDD rats (P <0.05), and there was no significant difference between testosterone levels . Conclusion During the gonadal sex determination period, the daily exposure dose of pregnant rats and the high dose of TCDD exposure can cause the histopathological changes of testes in adult male rats. The thickness of spermatogenic cells in testes is thin and the spermatogenesis is impaired, which may affect the spermatogenesis Generated, resulting in lower male reproductive capacity.